Gastric and small-bowel dysfunction can include gastroparesis, functional dyspepsia, and even irritable bowel syndrome. Patients with symptoms suggesting these disorders are commonly encountered by a variety of physicians, especially gastroenterologists. In most patients, the physical examination and upper endoscopy are normal, and thus symptoms are suggested to be from a motility disorder or a functional gastrointestinal disorder. Further evaluation directed at evaluating the stomach and small-bowel motility may help the clinician to arrive at a correct diagnosis enabling proper treatment of the patient. This article covers several tests that are used to evaluate gastric and small-bowel motility in patients, either in clinical evaluation or in clinical research.